Developer for silver salt diffusion transfer photography

ABSTRACT

A developer for diffusion transfer photography, which comprises an alkali, a silver halide solvent and a compound represented by the following general formula,   IN WHICH R represents an alkyl group, an alkoxyalkyl group, an alkoxyalkoxyalkyl group, an alkenyl group or a tetrahydrofurfuryl group.

United States Patent [1 1 Tanaka et a].

[111 3,864,131 [451 Feb. 4, 1975 DEVELOPER FOR SILVER SALT DIFFUSION TRANSFER PHOTOGRAPHY [75] Inventors: Mitsugu Tanalra; Katsumi Hayashi;

Atsuaki Arai, all of Ashigara, Japan [73] Assignee: Fuji Photo Film Co., Ltd.,

Kanagawa, Japan [22] Filed: Dec. 26, 1973 [21] Appl. No: 427,878

[30] Foreign Application Priority Data Dec. 25, l972 Japan 47-259 [56] References Cited UNITED STATES PATENTS 3,619,185 ll/l97l Kasman 96/29 R 3,765,889 10/1973 Young i o/29R Primary ExaminerMary F. Kelley Attorney, Agent, or Firm-Sughrue, Rothwell, Mion, Zinn & MacPeak [57] ABSTRACT A developer for diffusion transfer photography. which comprises an alkali, a silver halide solvent and a cOmpound represented by the following general formula,

[ J-cHZ-N-OEQ in which R represents an alkyl group, an alkoxyalkyl group, an alkoxyalkoxyalkyl group, an alkenyl group or a tetrahydrofurfuryl group.

7 Claims, No Drawings BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION This invention relates to a developer for lightsensitive silver halide materials and, more particularly, it is concerned with a developer for the silver salt diffu sion transfer photography, which uses a new compound as a developing agent.

2. DESCRIPTION OF THE PRIOR ART The silver salt diffusion transfer photographic process is a well known technique. As disclosed in US. Pat. No. 2,352,014, for instance, an exposed silver halide emulsion layer is contacted for a certain time with an image receiving material having a receiving layer containing silver precipitating nuclei through a diffusion transfer developer. At this time, the exposed silver halide is reduced to silver by a developing agent in the developer, while the non-exposed silver halide is reacted with a silver halide solvent in the developer to form a silver complex soluble in the aqueous alkali solution, which diffuses to the receiving layer where it is contacted with the silver precipitating nuclei and is reduced to silver. A positive image of an original is thus formed on the receiving layer.

As is apparent from the above description, the developer used in such a silver salt diffusion transfer photographic process contains a developing agent, a silver halide solvent and an alkali as essential components. As these essential components, hydroxy amines have hitherto been used often as a developing agent. This is due to an advantage that even if a hydroxy amine, contained in the receiving layer after the processing, is oxidized, the oxidized product is substantially colorless and the resulting image is not spoiled thereby.

However, known hydroxy amines emit a very unpleasant odor. Furthermore, they have a low solubility in aqueous alkali solutions and, therefore, cannot give an image having a sufficient density and gradation.

Thus, it is an object of this invention to provide a developer for diffusion transfer photography, which contains anew developing agent.

It is another object of the invention to provide a developer for diffusion transfer photography, which has a high solubility in aqueous alkali solutions and is capable of giving an image having a desirable density and gradation.

SUMMARY OF THE INVENTION We, the inventors, have made efforts to accomplish the above described objects and, consequently, reached the present invention.

The present invention,'provides a developer for diffusion transfer photography, which comprises an alkali, a silver halide solvent and a compound represented by the following general formula,

I LOH; -N-OH in which R represent an alkyl group, an alkoxyalkyl group, an alkoxyalkoxyalkyl group. an alkenyl group or a tetrahydrofurfuryl group.

DETAILED DESCRIPTION OF THE INVENTION In the above general formula, the number of carbon atoms of R is not particularly limited, and any compound can preferably be used in which about lg or more is soluble in 100g of an about 5 weight aqueous solution of alkali. In general, 1 to 4 carbon atoms are preferred for R.

In a preferred embodiment, R is an alkyl group such as a methyl, ethyl, propyl or butyl group, an alkoxyalkyl group such as a methoxymethyl, ethoxymethyl, methoxyethyl or ethoxyethyl group, an alkoxyalkoxyalkyl group such as a methoxymethoxymethyl or methoxymethoxyethyl group. an alkcnyl group such as an allyl group or a tetrahydrofurfuryl group.

Examples of compounds represented by the above described general formula are as follows:

1. N-Ethyl-Ntetrahydrofurfurylhydroxylamine 2. N-n-Butyl-N-tetrahydrofurfurylhydroxylamine 3. N-Methoxyethyl-N-tetrahydrofurfurylhydroxylamine 4. N-Ethoxyethyl-N-tetrahydrofurfurylhydroxylamine 5. N-Allyl-N-tetrahydrofurfurylhydroxylamine 6. N,N-Ditetrahydrofurfurylhydroxylamine These compounds can be synthesized by oxidizing a corresponding secondary amine such as N-ethyl-N-tetrahydrofurfurylamine, N-n-butyl-N-tetrahydrofurfurylamine, N-allyl-N-tetrahydrofurfuryl-amine, etc., with a suitable oxidizer, for example, hydrogen peroxide or an organic peracid such as peracetic acid or perbenzoic acid. Suitable solvents which can be used are water or alcohols such as methanol, ethanol, propanol or butanol, etc. Most alcohols can be suitably used but, where hydrogen peroxide is used as the oxidizing agent, preferably a lower alcohol is employed. The amine concentration suitably ranges from 5 to 50 wt preferably 20 to 40 wt A suitable molar ratio of amine to oxidizing agent which can be used is 0.2:1 to 2:1. The reaction is generally conducted at a temperature of about 5 to C., preferably 40 to 50C, with a reaction time of about 10 minutes to 10 hours, preferably 1 to 2 hours.

The synthesis of examples of these compounds can be as follows:

SYNTHESIS EXAMPLE I 51g of N-ethyl-N-tetrahydrofurfurylamine and 50ml of water were placed in a flask and then 40g of a 35% hydrogen peroxide aqueous solution was gradually added for a period of about 30 minutes with stirring. After the addition, the stirring was continued for about 2 hours while keeping the reaction solution at a temperature of 45 50C. The reaction solution was then extracted with chloroform and the resulting chloroform solution was dried with anhydrous sodium sulfate. The chloroform was distilled off and the residue was subjected to distillation under reduced pressure to obtain a fraction boiling at 79 80C/0.6 mmHg. Compound (I) is thus prepared in a yield of 25%.

SYNTHESIS EXAMPLE 2 Using 31g of N-ethoxyethyl-N-tetrahydrofurfurylamine, 18ml of water and 18g ofa 35% hydrogen perox ide solution, Compound (4) boiling at 97 98C/0.3 mmHg was prepared with a yield of 30% in a similar manner to Synthesis Example 1.

SYNTHESIS EXAMPLE 3 35g of N-allyl-N-tetrahydrofurfurylamine, 20ml of water and 25g of a 35% hydrogen peroxide solution was used and Compound boiling at 82 84C/0.5 mmHg was prepared with a yield of 23% in a similar manner to Synthesis Example 1.

Other compounds of the general formula can similarly be synthesized. These developing agents can be used alone or in admixture and, preferably, in a proportion of about 0.5 to 35% by weight, more preferably 2 to by weight, based on the developer used.

As the silver halide solvent of the invention, any of the conventional silver halide solvents as disclosed in U.S. Pat. Nos. 2,603,565 and 2,857,274 can be used, for example, thiosulfates such as sodium thiosulfate, potassium thiosulfate and ammonium thiosulfate, thiocyanates such as potassium thiocyanate and ammonium thiocyanate, thiourea, and thioglycolic acid. In addition to the above described sulfurcontaining silver halide solvents, sulfur-free nitrogen-containing compounds as disclosed in U.S. Pat. Nos. 2,603,565 and 3,345,167-can be used as the silver halide solvent. Examples of these silver halide solvents are cyclic imide compounds such as cyanuric acid, barbituric acid, uracil, 4-methyluracil, urazole, hydantoin and succinimide and amine compounds such as ethylamine, diethylamine, triethanolamine, monoethanolamine, ethylenediamine and aminoethylethanolamine. When such a sulfur-free nitrogen-containing compound is used for the developer of the invention, an image obtained after the processing is less contaminated with the passage of time. These silver halide solvents can be used alone or in admixture and, preferably, in a proportion of about l to 40% by weight, particularly, about 5 to based on the developer.

As the alkali of the invention, for example, alkali metal hydroxides, such as sodium hydroxide and potassium hydroxide, are used in such an amount that the pH of the developer is 10 or higher, preferably, 12 or higher. Other known alkalis can be used than the above described alkali metal hydroxides, but alkali metal hydroxides are preferred from the standpoint of controlling the pH.

Moreover, a viscosity increasing agent is preferably incorporated in the developer of the invention, so that the developer can readily and uniformly be spread between the silver halide emulsion and the receiving material. Examples of such are disclosed in U.S. Pat. Nos. 2,603,565 and 2,759,825. Illustrative viscosity increasing agents are methyl cellulose, hydroxyethyl cellulose and carboxymethyl cellulose. These compounds can be used alone or in admixture in such a manner that the viscosity of the developer is about 1000 to 20000cp at C.

In addition, various additives such as toning agents, fog inhibitors and antioxidants can be incorporated in the developer of the invention. As the toning agent,'any of the compounds which have conventionally been used for diffusion transfer photography as disclosed in U.S. Pat. Nos. 2,987,396, 3,053,657; 3,160,560 and 3,577,240, for example, 1-phenyl-5-mercaptotetrazole, 5-mercapto-2-mercapto-l,3,4-thiadiazole and the triazole compounds described in Japanese Patent Publication No. 2601/1968, such as 3-morpholinomethyl-1- phenyl-1,3,4-triazole, 5-methyl-3-.morpholinomethy1- l-phenyl-l ,3 ,4-triazole-4-ine-2-thione and 3- 4 hydroxymethyl-S-methyl-l ,3,4-triazole-4-ine-2thione can be used. As a fog inhibitor, for example, potassium bromide 0r 6benzoimidazole can be used and as an antioxidant, potassium sulfite, sodium-sulfite, sodium bisulfite, sodium metabisulfite, sodium benzenesulfinate, ascorbic acid, dihydroxybenzene and phenol can be used as disclosed in U.S. Pat. Nos. 3,295,972; 3,343,958 and 3,576,629.

After the development, zinc or a zinc compound can be incorporated in the developer ofthe invention as the occasion demands, for the purpose of easily and completely separating the silver halide emulsion layer and the receiving layer as disclosed in U.S. Pat, No. 3,295,972. Illustrative of the zinc compound are zinc chloride, zinc oxide, zinc hydroxide, zinc sulfate and zinc carbonate. Of course, other known stripping agents can be used. However, zinc compounds are preferred and preferably are used in a proportion of about 7 X 10' to 0.3 mol, particularly, 7 X 10 to 0.15 mol, per g of the developer.

As the silver halide of the silver halide emulsion which can be treated with the developer of the invention together with the receiving material, for example, silver chloride, silver bromide, silver chlorobromide, silver iodobromide and silver chloroiodobromide, which are well known in the art, can be used. In the silver halide emulsion various additives may be incorporated such chemical sensitizers as disclosed in U.S. Pat. Nos. 2,399,083; 2,540,085; 2,597,856; 2,597,915;

2,521,926; 2,694,637; 2,983,610 and 3,201,254, optical sensitizers as disclosed in U.S. Pat. Nos. 2,493,748;

3,635,721 and 3,694,217, fog inhibitors as disclosed in U.S. Pat. Nos, 1,758,576; 2,110,178; 2,131,038; 2,173,628; 2,697,040; 2,304,962; 2,324,123; 2,394,198; 2,444,605; 2,444,606; 2,444,607; 2,444,608; 2,566,245; 2,694,716; 2,697,099; 2,708,162; 2,728,663; 2,728,664; 2,728,665; 2,476,536; 2,824,001; 2,843,491; 2,886,437; 3,052,544; 3,137,577; 3,220,839; 3,226,231; 3,236,652; 3,251,691; 3,252,799; 3,287,135;

3,326,681; 3,420,668 and 3,622,339 and coating aids as disclosed in U.S. Pat. Nos. 2,271,623; 2,240,472; 2,288,226; 2,739,891; 3,068,101; 3,158,484; 3,201,253; 3,210,191; 3,294,540; 3,415,649; 3,441,413; 3,442,654; 3,475,174 and 3,545,974. As the optical sensitizer, various dyes can be used, for example, the cyanines, merocyanines, styryls and hemicyanines. Such silver halide emulsion is provided onto a support member to provide a light-sensitive material. Suitable supports are well known in the art and are described in detail in the above referenced patents.

On the other hand, the receiving material comprises a receiving layer on a suitable support, for example, a baryta paper or a polyethylene- 0r polystyrenelaminated paper. The receiving layer comprises a dispersion of silver precipitating nuclei in a natural or synthetic resin or a mixture thereof, for example, as disclosed in US, Pat. No. 3,607,269. As the silver precipitating nuclei, known materials can be used, for example, the metal sulfides, the metal selenides, the metal thioxalates, the metal thioacetamides and the colloidal metals as described in U.S. Pat. No. 2,698,237. Furthermore, a special receiving material can preferably be used which is prepared by providing a support at least the surface of which consists of a cellulose organic acid ester, hydrolysing the organic acid ester to render the surface alkali permeable and incorporating therein the silver precipitating nuclei as disclosed in U.S. Pat. No. 3,607,269.

The developing agent represented by the foregoing general formula, used in the developer of the invention is substantially free from any unpleasant odors such as fishey odors and has a higher solubility in an aqueous alkali solution as compared with known hydroxy amines, such as N-N-diethylhydroxylamine and N,N- dimethoxyethylhydroxylamine. Therefore, the developer of the invention does not emit an unpleasant odor and provides an image having a desirable density and gradation through diffusion transfer development.

The following examples are given to illustrate the invention in greater detail without limiting the same. Unless otherwise indicated, all parts, percents, ratios, etc., are by weight.

EXAMPLES 1. Preparation of Support: Onto an original paper (weight: 12Og/cm thickness: 0.125mm) a solution having the following composition was coated twice so as to provide a thickness of microns on a dry basis and dried:

Cellulose Acetate* (manufactured g by Daicell Co., Ltd. Acetylation degree: 55 i0.5'/r) Methanol 50 ml Methylene Chloride 2071 by weight aqueous solution: viscosity of 35 sec, ASTM Method E laminated with a polyethylene layer in a thickness of 20 1 microns was subjected to corona discharge to render the surface thereof hydrophilic. A silver iodobromide emulsion (Br, mol%. l, 5 mol%) was coated on the surface in a quantity of 12mg/1O0cm as silver. Furthermore, an aqueous solution of gelatin was coated onto the silver iodobromide layer to provide a thickness of 0.5 micron on a dry basis as a protective layer and then dried. 4. Development The receiving material was superimposed on the emulsion surface of the imagewise exposed silver halide light-sensitive material and between them, a developer having the composition as shown in Table l was spread in a thickness of microns.

Table 1 Developer Compound A Water 700 700 N-Ethyl-N-tetrahydrofurfurylhydroxylamine 32 NEthoxyethyl-N-tetrahydrofurfurylhydroxylaminc 35 Uracil 82 82 Aminoethylethanolamine 4 4 Sodium Hydroxide 5 5 Hydroxyethyl Cellulose" 30 30 Zinc Hydroxide 5 5 1% by weight aqueous solution-viscosity at 25C of 501) up: Degree of substitution. 2.5

The developer was prepared by mixing these compounds in a stream of nitrogen. After the developer was spread, the silver halide light-sensitive material and receiving material were stripped respectively after 20 seconds and 40 seconds. The reflection density at the maximum density (Dmax) and the color tone of an image thus obtained on the receiving material are shown in Table 2. The measurement of the reflection density was carried out using a P-type Densitometer made by the Fuji Photo Film Co., Ltd.

Table 2 Developer Color Tone Blue-Black Blue-Black Dmax (developing time: 20 seconds) I 1.69 Dmax (developing time: 40 seconds) 1.85 1.80

The Developers A and B are transparent solutions free from a fishey odor. As is evident from the results in mula,

in which R represents an alkyl group, an alkoxyalkyl group, an alkoxyalkoxyalkyl group, an alkenyl group or a tetrahydrofurfuryl group.

2. The developer of claim 1, wherein R has 1 to 4 carbon atoms.

3. The developer of claim 1, wherein said alkyl group is a methyl group, an ethyl group, a propyl group or a butyl group, wherein said alkoxyalkyl group is a methoxymethyl group, an ethoxymethyl group, a methoxyethyl group, or an ethoxyethyl group, wherein said alkoxyalkoxyalkyl group is a methoxymethox- N-allyl-N- or MN- amount of from about 0.5 to 35% by weight, based on N-ethoxyethyl-N- the weight of said developer.

6. The developer of claim 1, wherein said alkali is an alkali metal hydroxide. wherein said silver halide sol- ,vent is a thiosulfate, a thiocyanate, thiourea, thioglycolic acid, a cyclic imide compound, or an amine.

7. The developer of claim 1, wherein said developer includes at least one of a viscosity increasing agent, a toning agent, a fog inhibitor. an antioxidant, and zinc or a zinc compound. 

2. The developer of claim 1, wherein R has 1 to 4 carbon atoms.
 3. The developer of claim 1, wherein said alkyl group is a methyl group, an ethyl group, a propyl group or a butyl group, wherein said alkoxyalkyl group is a methoxymethyl group, an ethoxymethyl group, a methoxyethyl group, or an ethoxyethyl group, wherein said alkoxyalkOxyalkyl group is a methoxymethoxymethyl group or a methoxymethoxyethyl group and wherein said alkenyl group is an allyl group.
 4. The developer of claim 1, wherein said compound having the general formula is N-ethyl-N-tetrahydrofurfurylhydroxylamine, N-n-butyl-N-tetrahydrofurfurylhydroxylamine, N-methoxyethyl-N-tetrahydrofurfurylhydroxylamine, N-ethoxyethyl-N-tetrahydrofurfurylhydroxylamine, N-allyl-N-tetrahydrofurfurylhydroxylamine or N,N-ditetrahydrofurfurylhydroxylamine.
 5. The developer of claim 1, wherein said compound of the general formula is present in said developer in an amount of from about 0.5 to 35% by weight, based on the weight of said developer.
 6. THE DEVELOPER OF CLAIM 1, WHEREIN SAID ALKALI IS AN ALKALI METAL HYDROXIDE, WHEREIN SAID SILVER HALIDE SOLVENT IS A THIOSULFATE, A THIOCYANATE, THIOUREA, THIOGLYCOLIC ACID, A CYCLIC IMIDE COMPOUND, OR AN AMINE.
 7. The developer of claim 1, wherein said developer includes at least one of a viscosity increasing agent, a toning agent, a fog inhibitor, an antioxidant, and zinc or a zinc compound. 